<html>
	<head>
		<style type="text/css">
			/*设置图片背景*/
			#bg{
				
			}
			.cell {
				width: 120px;
				height: 100px;
				margin: 1px;
				border: 1px solid black;
				/*向左浮动*/
				
			}
			.redborder {
				border-color: red;
			}
			/*清浮动*/
			.clearfix:after{
				
				
				
			}
		</style>
	</head>
	<body>
		<div id="bg" class="clearfix">
			<div class="cell redborder">1</div>
			<div class="cell redborder">2</div>
			<div class="cell redborder">3</div>
			<div class="cell redborder">4</div>
		</div>
	</body>
</html>
